This invention relates to ceiling fans and more particularly to the isolation of the blades of a ceiling fan from vibrations of the drive motor.
The relatively widespread use of ceiling fans as comfort conditioning and air flow devices has resulted in the use of ceiling fans where motor-induced noises can no longer be tolerated. Paddle blade type ceiling fans are particularly susceptible to the transmission of motor-induced noises since by reason of their large area and length, the blades tend to act as resonating or sound transmitting devices, and thus tend to impart into the air, as noise, vibrations or the like which the blades receive from the drive motor.
The drive motors themselves, while relatively quiet by themselves, nevertheless when used to drive ceiling fan blades can impart objectionable noises to the surrounding atmosphere through the blades. Thus, a noisy stator caused for example by slightly loose stator laminations, which would produce an otherwise relatively unobjectionable and unnoticeable stator hum, may at times be transmitted through the motor structure through the blade-mounting cage or rotor to the blades themselves and produce an objectionably loud noise. Similarly, rotor vibrations or noises and bearing noises may be amplified by the blades and become objectionable.